As a long time proud user of home automation and home energy monitoring systems, I'll share my perspective and make a recommendation.
I installed Efergy three years ago. I installed The Energy Detective about 18 months ago.
Efergy requires transmitters outside of your cabinet that plug into the CTs inside. Depending on what generation of their product you buy you may have to change batteries, or may have to plug in a wall adapter to an outlet to power them.
Because of the price tag, I did much research before buying in to TED. I considered designing my own with CTs and an rPI. I was aware of systems that tried to pick up on 'noise signatures' of appliances, but I don't trust that they would be accurate, or be able to distinguish my loads from those of the couple neighbors on the same transformer. I also feel uneasy about appliance/circuit level data leaving my possession. The one device I recall seeing that did that kind of signal analysis seemed very expensive at the time, gimmicky, and I can't find the company any more, so I think I chose right when I went with TED.
TED comes with insulated snap-around CTs for the utility main breaker connection of course, but to reduce cost and clutter per branch circuit, you're expected to pass each load wire you want to monitor through a solid doughnut shaped insulated CT. There's special instructions for split phase circuits, or combining the measurements of multiple circuits. The install process is documented well and the manual is short and to the point.
TED lets you monitor two main breaker cabinets, local generation, and 32 branch circuits, concurrently. All data is transmitted over the power-line to a receiver unit with Ethernet that stores the data, serves a web application locally, and even sends email notifications of thresholds you set, directly from your own network with NO dependence on TED the company's infrastructure (the only offering with that level of independence).
TED additionally offers a free cloud service, but it is not necessary if you don't care to view it from outside your house, or if you know how to securely proxy connections in. (PROTIP, I wouldn't want my TED unit publicly accessible. I don't expect it has been security hardened.)
Both TED ad Efergy have been finicky from time to time. TED's tech support has been WAY better though. Efergy took MONTHS to resolve account/database issues in their cloud app, which is the ONLY way to view data on their platform. I had to track down London office numbers and time my calls to get to anyone at Efergy. TED gets back within a business day.
TED looks way better designed to me from a safety perspective, and depends on no batteries. Unlike Efergy, TED doesn't have any wires that run through the wall of the breaker cabinet.
TED can bring a lot of extra wire into your breaker cabinet though if you max your system out like I did. I used adhesive backed pads and zip ties to route the wiring. Some of my CTs are monitored by a 'brain box' in the opposite cabinet so I used solid conduit to pass those wires through. I can see flashing light from the heartbeat and tx LEDs shining through the gap between the last breaker and the front panel which is a little annoying. I might be concerned about having active electronics inside the panel, but that cat was out of the bag when arc faults came along.
All in all, I still think it looks crowded, but I find it tolerable, and I do not regret the expense in time or money.
If you have only a single panel and want it to look as tidy as possible, you might consider adding an enclosure adjacent to it connected via conduit and placing all of the TED electronics in that. The wires are probably long enough.
CTs (Make sure to get these the right direction around):
Left Panel sensor wire management:
Right Panel sensor wire management: